"I am excited and honoured to have been asked to lead AstraZeneca," Mr Soriot said. "No one is blind to the challenges that confront the pharmaceutical sector and this company, but the underlying strengths of AstraZeneca in delivering on its strategy are clear. AstraZeneca will continue to make a positive difference to patients over the longer term and I'm looking forward to playing my part in shaping that future."

Anglo-Swedish drugmaker AstraZeneca has been without a permanent chief executive since June 1, following the abrupt departure of David Brennan, who was criticised by investors for failing to do enough to shore up the group as a wave of drug patents expired.

AstraZeneca's chief financial officer, Simon Lowth, has acted as interim chief executive and will continue to do so until Mr Soriot arrives.

After that, AstraZeneca said Mr Lowth would resume his duties as finance chief and continue to serve as an executive director, although there is likely to be speculation over how long he will remain, since he was also considered a candidate for chief executive, Reuters reports.

Britain's second-biggest drugmaker has suffered repeated drug development setbacks, stoking fears about its long-term prospects given loss of exclusivity on key medicines, which exposes the group to generic competition and declining sales.

Roche, by contrast, has had a successful record of drug development and Mr Soriot has been at the centre of that innovation as a former head of Roche's US biotech unit Genentech.

Swiss-based Roche said diagnostics boss Daniel O'Day would take over as head of its dominant pharma division to replace Soriot and Roland Diggelmann, currently head of the Asia-Pacific region in the diagnostics division, would replace O'Day.

Meanwhile, the European Commission has approved Zinforotm for adult patients with serious skin infections. The ruling makes the antibiotic the only approved treatment "with demonstrated clinical efficacy" against MRSA.